The present invention pertains to round balers with a twine wrapping apparatus that includes twine wrapping arms and a twine cutting apparatus. More particularly, the present invention pertains to an improved twine wrapping apparatus that has a wiper mounted to the twine wrapping arms wherein the wiper periodically wipes or clears accumulating trash from the shear bar of the cutting apparatus.
Typical round balers (also referred to simply as a xe2x80x9cbalersxe2x80x9d), such as disclosed in U.S. Pat. No. 6,209,450 to Naaktgeboren et al., are agricultural machines that pick up a cut crop material from the ground and form it into a compacted round bale in a bale-forming chamber. When the bale has been sufficiently compacted to a desired density or a desired size depending on the baler construction, appropriate sensors, such as a bale density or bale size sensor, send signals to a controller. The controller subsequently sends a signal to an operator""s panel to stop forward motion of the baler so that a bale wrapping operation can be performed. In this way, the formed bale is wrapped with netting or twine to produce a completed, wrapped bale.
As is conventionally known, the wrapping operation is performed by a bale wrapping mechanism controlled by a bale wrapping algorithm preprogrammed into a controller (i.e., microprocessor) that is part of the baler. The bale wrapping mechanism has two twine wrapping tubes/arms, wherein each tube/arm dispenses a single strand of twine. When a wrap cycle is initiated, the end of each twine strand dangles from its twine tube and is caught by the bale as the bale continues to rotate in the bale forming chamber. As the bale rotates, the caught ends of the twine strands rotate with the bale and twine is wrapped around the bale. At the end of a wrap cycle, a tying operation is performed as is generally known. Before the completed, wrapped bale can be expelled from the baler, the twine strands must be cut.
The bale wrapping mechanism includes a knife assembly having a cutting edge, and a shear bar that cooperates with the cutting edge of the knife assembly. The knife assembly generally includes two knives (i.e., a right knife and a left knife), each with its own cutting edge. At the start of a wrap cycle, the twine strands are positioned between the knife assembly and the shear bar, and the knife assembly and shear bar are spaced apart so that the twine strands can move freely between the knife assembly and the shear bar. At the end of the wrap cycle (i.e., after the twine ends have been secured by tying), the knife assembly moves by translation or rotation to engage the shear bar, so that the cutting edge of each knife of the knife assembly pinches a respective one of the twine strands against the shear bar, and the twine strands are cut.
One drawback of the prior art bale wrapping mechanism is that during the bale forming operation trash (i.e. errant cut crop material and other debris) tends to accumulate on inner surfaces of the bale wrapping mechanism. This includes accumulation of trash on the shear bar of the knife assembly. When enough trash accumulates on the surface of the shear bar, the trash begins to interfere with the cutting efficiency of the knife assembly. Specifically, the trash prevents the knife edge of the knife assembly""s pivoting knife to properly engage the shear bar and cut the twine at the end of the bale wrapping cycle. When this happens, the twine wrapping mechanism is not able to properly expel the wrapped bale and start another bale wrapping cycle. Thus, there is a need for a shear bar cleaning mechanism that periodically removes accumulating trash material from the surface of the shear bar in round balers having two twine arms, wherein each twine arm dispenses a single twine strand. Preferably, the cleaning mechanism""s periodic removal of trash from the shear bar is timed to occur soon before the twine cutting operation to optimize cutting efficiency. In addition, there is a need for a shear bar cleaning mechanism that can be utilized by the new round balers that include a bale wrapping apparatus having four twine wrapping tubes and two twine arms, wherein each tube dispenses a single strand of twine and each twine arm carries two twine wrapping tubes. The advantage of a round baler having four twine strands provided for wrapping over the conventional two twine strands is that four strands permit completion of the wrapping operation in less time than can be achieved when only two strands are available; however, the drawback of these newer four twine strand dispensing bale wrapping mechanisms is that they are more sensitive to the effects of trash accumulating on the shear bars so they have a greater need for a shear bar cleaning mechanism.
For these reasons, it would be advantageous to have a bale wrapping mechanism that includes two twine arms, a knife assembly, and a shear bar cleaning mechanism, wherein the shear bar cleaning mechanism periodically clears the shear bar of accumulating trash to ensure reliable severing of all of the twine strands.
The present invention endeavors to provide a round baler with an improved bale wrapping apparatus with a knife assembly and a shear bar cleaning mechanism to periodically clear the shear bar of accumulating trash to ensure reliable cutting of all of the twine strands.
Accordingly, an object of the present invention is to overcome the disadvantages of prior art round balers.
Another object of the present invention is to provide a round baler with an improved bale wrapping apparatus having a knife assembly, wherein the bale wrapping apparatus has two twine wrapping arms, and each twine wrapping arm has a wiper mounted thereon so that each wiper clears accumulating trash from a surface of a respective shear bar when the twine arm moves from a first position to a cutting position.
A still further object of the present invention is to provide a round baler with an improved bale wrapping apparatus, having wipers mounted to each twine wrapping arm and a knife assembly, that is durable and that reliably cuts all of the twine strands.
Yet another object of the present invention is to provide a round baler with an improved bale wrapping apparatus, having wipers mounted to each twine wrapping arm and a knife assembly, that is easy to maintain.
In accordance with the above objectives, one embodiment of the present invention provides a round baler, including a housing with a bale chamber defined therein, and a bale wrapping apparatus disposed in the housing adjacent the bale chamber to wrap a rotating bale formed in the chamber, the bale wrapping apparatus comprising: (a) a rotating first twine supply roll defining a first twine strand; (b) a first twine dispensing arm presenting the first twine strand; (c) a first shear bar connected to the housing, wherein the first shear bar has a cutting surface; (d) a first knife assembly rotatingly connected to the housing by an elongated bar and rotatable from a first position to a second cutting position in contact with the cutting surface of the first shear bar, wherein the first twine dispensing arm is movable from a first position presenting the first twine strand to the bale to a second cutting position wherein first twine strand extends transversely between the first shear bar and the first knife assembly; and (e) a first wiper mounted to the first twine dispensing arm so that when the first twine dispensing arm moves from the first position to the cutting position, the first wiper engages the cutting surface of the first shear bar to wipe the cutting surface of the first shear bar.
In accordance with a second embodiment, the first embodiment is modified so that the first wiper is mounted to an outside edge of the first twine dispensing arm.
In accordance with a third embodiment, the first embodiment is modified to further include: (f) a rotating second twine supply roll defining a second twine strand; (g) a second twine dispensing arm presenting the second twine strand; (h) a second shear bar connected to the housing, wherein the second shear bar has a cutting surface; (i) a second knife assembly rotatingly connected to the housing by the elongated bar and rotatable from a first position to a second cutting position in contact with the cutting surface of the second shear bar, wherein the second twine dispensing arm is movable from a first position presenting the second twine strand to the bale to a second cutting position wherein the second twine strand extends transversely between the second shear bar and the second knife assembly; and (j) a second wiper mounted to the second twine dispensing arm so that when the second twine dispensing arm moves from the first position to the cutting position, the second wiper engages the cutting surface of the second shear bar to wipe the cutting surface of the second shear bar.
In accordance with a fourth embodiment, the third embodiment is further modified so that the first wiper is mounted to an outside edge of the first twine dispensing arm and the second wiper is mounted to an outside edge of the second twine dispensing arm.
In accordance with a fifth embodiment, the fourth embodiment is modified so that the bale wrapping apparatus further includes: (k) a rotating third twine supply roll defining a third twine strand and a rotating fourth twine supply roll defining a fourth twine strand, wherein the first twine dispensing arm presents the third twine strand and the second twine dispensing arm presents the fourth twine strand so that the first twine dispensing arm presents the third twine strand to the bale when in the first position and the third twine strand extends transversely between the first shear bar and the first knife assembly when the first twine dispensing arm is in the cutting position, and wherein the second twine dispensing arm presents the fourth twine strand to the bale when in the first position and the fourth twine strand extends transversely between the second shear bar and the second knife assembly when the second twine dispensing arm is in the cutting position.
In accordance with a sixth embodiment, the first embodiment is further modified so that the first wiper is a brush.
In accordance with a seventh embodiment, the first embodiment is further modified so that the first wiper comprises a piece of resilient material.
In accordance with an eighth embodiment, the third embodiment is further modified so that the both the first wiper and the second wiper are brushes.
In accordance with a ninth embodiment, the third embodiment is further modified so that each of the first wiper and the second wiper comprise a piece of resilient material.
Further objects, features and advantages of the present invention will become apparent from the Detailed Description of Preferred Embodiments, which follows, when considered together with the attached drawings.